Comparison of Clinical and Radiological Features of Aspergillus, Zygomycosis, and Fusarium Pneumonia in Neutropenic Patients

Abstract

Background: Opportunistic fungal pneumonia in neutropenic patients due to hematologic malignancy or bone marrow transplant continues to rise, and the diagnosis remains challenging. We sought to compare the clinical and early radiological patterns of 3 fungi (Aspergillus, Fusarium, and zygomycosis) in this population to facilitate early diagnosis and improve choice of early empiric therapy before culture results are available. Methods: This is a retrospective chart review study conducted between January 1999 and June 2010 in neutropenic patients with fungal pneumonia. Clinical and radiological features, duration of neutropenia, underlying illness, culture results, treatment choice, and outcome were recorded for each patient. Results: Total of 74 patients with fungal pneumonia met inclusion criteria: 27 had Aspergillus, 25 had Fusarium, and 22 had zygomycosis pneumonia. The following were the findings: & Underlying diagnosis: Acute myeloid leukemia was the most common underlying diagnosis in any fungal pneumonia, present in 42 (57%) of the 74 patients. & Clinical features: Toe cellulitis was present in 34% of Fusarium pneumonia cases. Blood culture positive for the fungus in 10% of the Fusarium cases. Other clinical features were reported in similar frequencies in all types of fungal pneumonia. & Radiological patterns: In 20 (80%) of 25 cases of Fusarium, early lung nodules were multiple (92) and small with an average diameter less than or equal to 1 cm at initial computed tomography scans (size: minimum 0.1, median 0.8, maximum 2.8 cm). Sixteen (67%) of 24 cases of early nodules caused by Aspergillus and 13 (72%) of 18 cases of early nodules caused by zygomycosis had a bigger size at diagnosis (size: minimum 0.3, median 1.8, maximum 4.3 cm for Aspergillus; and minimum 0.5, median 2.1, maximum 4.5 cm for zygomycosis) (P G 0.0001) and were few in number. Fusarium lung nodules had a scattered (central and peripheral) distribution in 76% of cases. Nodules caused by Aspergillus and zygomycosis were located peripherally, in 75% and 78% of cases respectively. & Duration of neutropenia: The median duration of neutropenia was shorter with an average of 18 days (minimum, median, maximum = 1, 10, 60 days, respectively) at the time of invasive Aspergillus diagnosis in contrast to that for Fusarium with an average of 48 days (minimum, median, maximum = 7, 26, 128 days, respectively) and an average of 45 days in cases due to zygomycosis (minimum, median, maximum = 4, 28.5, 105 days, respectively) (P G 0.0001). & Initial treatment and outcome: Voriconazole was used empirically initially in 53 (72%) of the 74 patients. Mortality at 3 months for all fungi was 64%, highest for zygomycosis (67%) followed by Aspergillus (63%) and Fusarium (55%). Conclusions: Clinical and radiological patterns and duration of neutropenia provide useful clues as to the nature of the fungal pneumonia in neutropenic patients. This can help better guide the choice of the initial empiric antifungal therapy and may help improve patient outcome.